The Montreal Impact is expanding its four-year-old soccer stadium to meet Major League Soccer standards at a fraction of the cost of the league’s newest venues.

The Impact moves up to MLS this season after playing last year in the North American Soccer League. Before that, the team competed for several seasons in the United Soccer Leagues.

The $23 million expansion, now under construction, will push Saputo Stadium’s seating from 13,034 to 20,341 and boost the number of suites from 16 to 35. The facility is next to Olympic Stadium and opened in 2008 at a cost of $17 million.

The team will play its first five home games at Olympic Stadium before moving back to Saputo Stadium in mid-June after the expansion is completed, said Richard Legendre, executive vice president. The first

At a total cost of $40 million, Saputo Stadium’s price tag is far below what it cost MLS clubs to build new stadiums in other markets. Livestrong Sporting Park and Red Bull Arena, built in 2011 and 2010, respectively, cost $200 million and $150 million.

With the province of Quebec financing the project, the Impact went lean with the expansion and decided against adding a stage, loading docks and other infrastructure upgrades to accommodate concerts and other special events.

Team officials saw those design elements at some of the 10 to 12 MLS stadiums they visited over the past year, but felt those extra features did not make good business sense in a market where Bell Centre is the dominant concert venue, Legendre said.

“To have two to three concerts during the summer doesn’t justify the additional investment, and physically, at Olympic Park, there was not much space to expand,” he said. “This will be soccer only. We made that choice.”

Saputo Stadium sits on the site of the old track and field practice facility for the 1976 Olympics, and the Impact was able to use part of the existing bleacher structure during original construction. As a result, the north-side stands sit lower than the south side, Legendre said.

Of the 7,000 new seats, 3,500 make up the new west grandstand, with an additional 1,250 seats in the southeast and southwest corners. About 1,000 seats were added to the east grandstand.

The existing roof will extend over the upper rows of each grandstand and cover about 7,000 total seats, including the middle sections on the north and south sides, where top-end season-ticket holders pay $70 a game

The team has sold about 70 percent of the suites, Legendre said. They run $22,000 a year for eight seats and $32,000 annually for 12 seats. Terms are three and six years. Game tickets are included, but food and drink is a separate cost.

There is space behind both goals to build a few more suites if needed, Legendre said.

The Impact will continue to use Olympic Stadium for bigger international matches. The club previously drew 55,000 for a CONCACAF Champions League quarterfinal game in 2009 and about 48,000 against AC Milan in 2010.